1. Field
Example embodiments of the present invention relate to an information processing technique for realizing a natural augmented reality effect by displaying an image in which a virtual object image is superimposed on a real space which is visible to a user, and more particularly to an information processing technique for enabling appearance of a virtual object while maintaining a natural augmented reality effect.
2. Description of the Background Art
A so-called augmented reality system is realized which displays, as if an object exists in a virtual space, an image in which a virtual object image is superimposed on a real world (a real space or a real environment). The augmented reality system provides a technique for displaying a virtual object in a real world, and the augmented reality system enables the virtual object to be displayed, without causing unnaturalness, by, for example, superimposing a previously generated image of the virtual object on a real space photographed by a camera. Japanese Laid-Open Patent Publication No. 2006-260602 (hereinafter, referred to as Document 1) discloses a game apparatus which displays a virtual object (character) which acts in cooperation with a motion of a real object (game card).
However, in the game apparatus disclosed in Document 1, the character is suddenly displayed on a screen when a game is started. Specifically, in this game apparatus, when a three-dimensional image representing the character is initially displayed for starting the game, a state of nothing being displayed is switched to a state of an image in which the three-dimensional image representing the character is superimposed on a frame image being displayed, or a state of a frame image being displayed is switched to a state of an image in which the three-dimensional image representing the character is superimposed on the frame image being displayed. When displays are switched in this manner, the three-dimensional image representing the character suddenly appears on the screen. Therefore, it is impossible to realize a natural augmented reality effect which enables a user to feel as if the three-dimensional image representing the character really exists in a real space.
In order to overcome the problems, in a game to which the augmented reality system is applied, it is important to enable appearance of a virtual character for starting a game while realizing a natural augmented reality effect. However, neither the game apparatus disclosed in Document 1 nor known techniques can solve these problems.